Electronic stethoscope system for telemedicine applications

ABSTRACT

An electronic stethoscope includes a housing configured for hand-held manipulation, a transducer supported by the housing and configured to sense auscultation signals at a first location, and a headset coupled to the housing and configured to deliver audio corresponding to the auscultation signals through earpieces on the headset. The electronic stethoscope further includes a processor disposed in the housing and configured to convert the auscultation signals to first digital signals representative of the auscultation signals and to wirelessly transmit the first digital signals from the electronic stethoscope via a secure digital network to a second location such that the audio corresponding to the auscultation signals is provided to headsets of one or more additional electronic stethoscopes at the second location in substantial real time with the sensing of the auscultation sounds at the first location.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Provisional Application No.61/300,285, filed Feb. 1, 2010 and International Application No.PCT/US2010/048745, filed Sep. 14, 2010, both hereby incorporated byreference in their entirety.

BACKGROUND

The present invention relates to telemedicine systems. Morespecifically, the present invention relates to electronic stethoscopesthat transmit signals over a telemedicine system in substantialreal-time via a secure digital network.

A variety of devices have been developed to detect sounds produced bythe body, such as heart and lung sounds. Known devices range fromprimarily mechanical devices, such as a stethoscope, to variouselectronic devices, such as microphones and transducers. Thestethoscope, for example, is a fundamental tool used in the diagnosis ofdiseases and conditions of the cardiovascular system. It serves as themost commonly employed technique for diagnosis of such diseases andconditions in primary health care and in circumstances wheresophisticated medical equipment is not available, such as remote areas.

Clinicians readily appreciate that detecting relevant cardiac symptomsand forming a diagnosis based on sounds heard through the stethoscope,for example, is a skill that can take years to acquire and refine. Thetask of acoustically detecting abnormal cardiac activity is complicatedby the fact that heart sounds are often separated from one another byvery short periods of time, and that signals characterizing cardiacdisorders are often less audible than normal heart sounds.

SUMMARY

In one aspect, the present invention relates to a telemedicine systemincluding a first electronic stethoscope comprising a housing configuredfor hand-held manipulation, a transducer that senses auscultationsignals at a first location, and a headset that delivers audiocorresponding to the auscultation signals through earpieces on theheadset. The telemedicine system further includes a second electronicstethoscope comprising a housing configured for hand-held manipulation,a transducer, and a headset that delivers audio through earpieces on theheadset. The first electronic stethoscope includes a processor thatconverts the auscultation signals to digital signals representative ofthe auscultation signals, and an antenna to wirelessly transmit thedigital signals to a second location via a secure digital network. Thesecond electronic stethoscope includes an antenna that receives thedigital signals representative of the auscultation signals at the secondlocation via the secure digital network, and a processor that convertsthe digital signals to audio corresponding to the auscultation signalsand delivers the audio through earpieces on the headset of the secondelectronic stethoscope in substantial real time with the sensing of theauscultation sounds at the first location.

In another aspect, the present invention relates to an electronicstethoscope including a housing configured for hand-held manipulation, atransducer supported by the housing and configured to sense auscultationsignals at a first location, and a headset coupled to the housing andconfigured to deliver audio corresponding to the auscultation signalsthrough earpieces on the headset. The electronic stethoscope furtherincludes a processor disposed in the housing and configured to convertthe auscultation signals to first digital signals representative of theauscultation signals and to wirelessly transmit the first digitalsignals from the electronic stethoscope via a secure digital network toa second location such that the audio corresponding to the auscultationsignals is provided to headsets of one or more remote electronicstethoscopes at the second location in substantial real time with thesensing of the auscultation sounds at the first location.

In a further aspect, the present invention relates to a telemedicinesystem including a local electronic stethoscope configured to senseauscultation signals from a patient and convert the auscultation signalsto digital signals representative of the auscultation signals. Thetelemedicine system further includes one or more additional electronicstethoscopes, and a secure network interface connecting the localelectronic stethoscope to the one or more additional electronicstethoscopes via a secure digital network. Each of the one or moreadditional electronic stethoscopes is configured to receive the digitalsignals representative of the auscultation signals via the securedigital network and to convert the digital signals to audiocorresponding to the auscultation signals. The audio is deliveredthrough earpieces on a headset of each of the one or more additionalelectronic stethoscopes in substantial real time with the sensing of theauscultation sounds by the local electronic stethoscope.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a telemedicine system according to anembodiment of the present invention.

FIG. 2 is a perspective view of an embodiment of an electronicstethoscope suitable for use in the telemedicine system shown in FIG. 1.

FIG. 3 is a front view of an embodiment of a system for interfacing withan electronic stethoscope at a patient or specialist site.

FIG. 4 is a screen shot of an embodiment of a user interface at thepatient site.

FIG. 5 is a screen shot of an embodiment of a user interface at thespecialist site.

FIG. 6 is a screen shot of a graphical user interface that may bedisplayed on the user interfaces shown in FIGS. 4 and 5.

FIG. 7 is a perspective view of an embodiment of a wireless chestpiecefor use in the telemedicine system shown in FIG. 1.

FIG. 8 is a perspective view of an embodiment of a wireless headset foruse in the telemedicine system shown in FIG. 1.

FIG. 9 is a diagrammatic view of a telemedicine system according toanother embodiment of the present invention.

While the invention is amenable to various modifications and alternativeforms, specific embodiments have been shown by way of example in thedrawings and are described in detail below. The intention, however, isnot to limit the invention to the particular embodiments described. Onthe contrary, the invention is intended to cover all modifications,equivalents, and alternatives falling within the scope of the inventionas defined by the appended claims.

DETAILED DESCRIPTION

FIG. 1 is a diagrammatic view of an embodiment of a telemedicine system10 including bioacoustic sensors 12, a patient site computer 14, apatient site software interface 16, a specialist site computer 22, and aspecialist site software interface 24. An optional wireless headset 25is also shown at the specialist site. The patient site bioacousticsensor 12 communicates with the patient site computer 14 wirelessly, andinteracts with the patient site computer 14 via the patient sitesoftware interface 16. The specialist site bioacoustic sensor 12communicates with the specialist site computer 22 wirelessly, andinteracts with the specialist site computer 22 via the specialist sitesoftware interface 24. The patient site software interface includes awireless interface 26 and a network port interface 27, and thespecialist site software interface includes a wireless interface 28 anda network port interface 29. The patient site computer 14 and thespecialist site computer 22 communicate with each other over theInternet I. In short, the bioacoustic sensors 12 communicate with eachother via the patient site computer 14, the specialist site computer 22,and the Internet I to allow a clinician or other medical specialistlocated remotely from the patient site to hear body sounds sensed from apatient at the patient site in substantial real-time. The transmissionis in “substantial real-time” due to any delays resulting from signalprocessing and transmission between the patient and specialist sitestethoscopes. Other sounds and information, such as voice signals, mayalso be transmitted in substantial real-time between the bioacousticsensors 12.

FIG. 2 is a perspective view of one embodiment of a bioacoustic sensor,an electronic stethoscope 12, suitable for use in the telemedicinesystem 10. The electronic stethoscope 12 includes ear tips 30 a, 30 b,ear tubes 32 a, 32 b, and a main tube 34. The main tube 34 is coupled toa main housing or chestpiece 36, which supports at least one sensor 38(not visible in FIG. 2). The sensor 38 is configured to sense soundsproduced by matter of biological origin, such as sounds produced by theheart, lungs, vocal cords, or other organs or tissues of the body. Incertain embodiments, the sensor 38 may be used to pick up voice soundsfrom the user of the electronic stethoscope 12 at the patient and/orspecialist sites. Other components that may be disposed in or on themain housing 36 include a power source, a microprocessor, signalprocessing circuitry (e.g., a digital signal processor), a keypad, agraphical user interface, and a communications device (e.g., a radio).In addition, the main housing 36 may include power management circuitrysuch as that described in U.S. Patent Application Publication No.2008/0232604, entitled “Power Management for Medical Sensing DevicesEmploying Multiple Sensor Signal Feature Detection,” which isincorporated herein by reference in its entirety.

The signal processing circuitry of the electronic stethoscope 12 may beconfigured to perform a variety of functions, ranging from simple tocomplex. For example, the signal processing circuitry may be configuredto perform relatively sophisticated analysis of bioacoustic signalsreceived from the sensor 38, such as body sound profile matching. Thesignal processing circuitry may perform various forms of statisticalanalysis on signals produced by the sensor 38. In such configurations,the signal processing circuitry may include a digital signal processor(DSP). As a further example, the signal processing circuitry may performselective frequency filtering to enhance different types of body soundssensed by the electronic stethoscope 12. The signal processing circuitryis further configured to convert the signals generated by the sensor 38to acoustic signals for transmission through the ear tubes 32 a, 32 bfor accurate and faithful reproduction of the body sounds through theear tips 30 a, 30 b. In some embodiments, the electronic stethoscope 12is configured to generate acoustic signals as described in U.S. Pat. No.6,134,331, entitled “Electronic Stethoscope,” U.S. Pat. No. 7,006,638,entitled “Electronic Stethoscope,” and/or U.S. Pat. No. 7,130,429,entitled “Method and an Apparatus for Processing Auscultation Signals,”each of which is incorporated by reference in its entirety.

In some embodiments, the sensor 38 of the electronic stethoscope isconfigured to modulate or generate an electrical signal in response todeformation of the transducer. Suitable transducers are those thatincorporate piezoelectric material (organic and/or inorganicpiezoelectric material) such as piezoelectric film, piezoresistivematerial, strain gauges, capacitive or inductive elements, a linearvariable differential transformer, and other materials or elements thatmodulate or generate an electrical signal in response to deformation.The sensor 38 may be planar or non-planar, such as in the case of acurved or corrugated configuration. Suitable piezo materials may includepolymer films, polymer foams, ceramic, composite materials orcombinations thereof. The sensor 38 may incorporate arrays oftransducers of the same or different transducer type and/or differenttransducer materials, all of which may be connected in series,individually, or in a multi-layered structure. Suitable transducers thatincorporate plural sensing elements having differing characteristicsand/or sensors with tailorable sensing characteristics are disclosed incommonly owned U.S. Patent Application Publication Nos. 2007/0113649 and2007/0113654, each of which is incorporated herein by reference in itsentirety.

The sensor 38 may be implemented using technologies other than thosethat employ electromagnetic energy or piezo materials. For example, thesound to be transduced may move a cantilever that has a highlyreflective surface, and a laser or optical beam of light shining on thissurface may be modulated. The intensity or other property of themodulated light may be received by a photodetector that outputs anelectrical signal for analysis. As a further example, one or moreaccelerometers may be employed to sense sound signals and produceelectrical signals corresponding to the sound signals.

The electronic stethoscope 12 also includes a user interface 40. Theuser interface 40 may include a number of mode and/or status indicatorsand mode and/or control switches. The switches may include volume orgain control switches and mode selection switches, for example. Theindicators may provide an indication of a selected filter mode, or otherinformation, such as battery and communication link status. Suchcommunication link status indication may be based on the error detection(e.g., CRC and other methods described below) performed by a computer14, 22 and/or the electronic stethoscope 12 at the patient or specialistsite. In preferred embodiments, only the occurrence of an error, and notthe lack thereof, is reported. For example, if errors are identified byeither the specialist site computer 22 and/or the specialist siteelectronic stethoscope 12, the specialist site electronic stethoscope 12may send a signal to the specialist site computer 22 that the datareceived by the specialist site electronic stethoscope 12 is not thesame as the data sent by the patient site electronic stethoscope 12. Theindication may then be provided by the user interface 40, which showsthe clinician at the specialist site that the sound being heard throughthe specialist site electronic stethoscope 12 is not a faithfulreproduction of the body sound signals sensed by the patient siteelectronic stethoscope 12. As used herein, the term “faithfulreproduction” means a digitally exact replica.

The electronic stethoscope 12 also includes an integrated communicationssystem to communicate signals wirelessly with the patient site computer14 or the specialist site computer 22. Information acquired by theelectronic stethoscope 12 during auscultation, for example, may betransmitted to the computer 14, 22. The computer 14, 22 may process theinformation to provide various output data, such as a visual, graphicaland/or audible representation of the information (e.g., heart rateindication, S1-S4 heart sounds), and/or diagnostic information regardinganomalous cardiac, lung, or other organ function (e.g., phonocardiogram,frequency spectrogram, cardiac murmurs such as those resulting fromvalve regurgitation or stenosis, breathing disorders such as pneumoniaor pulmonary edema), or other organ pathology.

The communications system may be used to establish a radio frequency(RF) communication link between the electronic stethoscope 12 and thecomputer 14 or 22 or other external device (e.g., personal computer,personal digital assistant (PDA), cell phone, netbook, etc.), as will bedescribed in more detail below. The communication link may beimplemented using a short-range wireless communication interface, suchas an interface conforming to a known communications standard, such as aBluetooth standard, IEEE 802 standards (e.g., IEEE 802.11), a ZigBee orsimilar specification, such as those based on the IEEE 802.15.4standard, or other public or proprietary wireless protocol. For example,in some embodiments, the communications system is a Class 1 or Class 2Bluetooth radio. Wireless communication may be implemented in mannersthat utilize one or several of the following energy forms:electromagnetic radiation, optical (including near infrared), andacoustic (including high frequency beyond average hearing limit). Insome embodiments, the communications system is employed to establish asecure communications link between the electronic stethoscope 12 and thecomputer.

In some embodiments, an antenna (not shown) for the wirelesscommunications system is integrated into the main housing 36. In orderto improve the communication link with the electronic stethoscope 12, anaperture 42 may be formed in the metal main housing 36 and covered witha more electromagnetically transparent material. For example, theaperture 42 can be covered with a polymeric member. A flashing lightsource (e.g., LED) may be mounted in the aperture to indicate that theconnection between the electronic stethoscope 12 and the computer isactive, and to remind the user of the electronic stethoscope 12 to notcover the aperture 42. A return signal strength indicator may beincluded on the user interface 40 to provide the strength of thecommunication link to the user while a connection with the computer isestablished. In some embodiments, a small parabolic reflector is placedunder the antenna to reflect signals transmitted from the antennanormally lost into the tissue of the patient, and to concentrate signalsreceived from the computer captured by the antenna. In an alternativeembodiment, the antenna is mounted in one of the ear tubes 32 a, 32 b orthe main tube 34 to locate the antenna higher and improve theline-of-sight with the computer. The antenna may include multiplebranches that are mountable on both sides of the ear tubes 32 a, 32 b toallow unobstructed signal communication under varying body orientations.

The electronic stethoscope 12 may also include a wired connection port44 to allow for a wired connection between the electronic stethoscope 12and the computer 14 or 22 or other external device (e.g., personalcomputer, personal digital assistant (PDA), cell phone, netbook, etc.).A conductor (electrical or optical) may be connected between the wiredconnection port 44 of the electronic stethoscope 12 and an appropriateconnector on the external device. The wired connection port 44 of theelectronic stethoscope 12, and any necessary interface circuitry, may beconfigured to communicate information in accordance with a variety ofprotocols, such as FireWire™ (IEEE 1394), USB, Mini USB, or othercommunications protocol. In addition, the connection port 44 may beconfigured to connect to a docking station that interfaces theelectronic stethoscope 12 with the computer 14 or 22. The attachment ofthe electronic stethoscope 12 to the cable or docking station cantrigger the automatic launch of control/application software on thecomputer 14 or 22 and/or allow sound or data files stored on theelectronic stethoscope 12 to upload or synchronize into the computer 14or 22. When connected, recharging power may also be delivered to theelectronic stethoscope 12 via the wired connection port 44.

An acoustic transducer or microphone 48 may also be integrated into thetop side (i.e., the side facing away from the sensor 38) of the mainhousing 36. The microphone 48 may be used to receive ambient sounds fromthe area surrounding the microphone 48. For example, the microphone 48may be used, in addition to or in lieu of sensor 38, to pick up voicesounds from the user of the electronic stethoscope 12 at the patientand/or specialist sites.

In some embodiments, the electronic stethoscope 12 includes anintegrated electronic storage medium that allows a user to store voicetracks, body sounds, or other recordings in the electronic stethoscope12 for later review. The electronic storage medium may further includevoice recognition data to identify the user or owner of the stethoscopeand speech recognition data to identify voice commands so that certainsettings (e.g., power, volume) of the electronic stethoscope 12 may bemodified in response to voice commands. Speech recognition voicecommands may also be used to transfer voice tracks, body sounds, orother recordings or files to a patient medical record database. In someembodiments, the electronic stethoscope is configured to transcribe thecontent of voice signals into records or other data files (e.g., patientmedical records), as described, for example, in U.S. Pat. No. 7,444,285(Forbes). The voice tracks may also be stored with sound tracks relatingto sensed body sounds such that the body sounds and voice tracks can beplayed back simultaneously through the ear tips 30 a, 30 b. In someembodiments, the user interface 40 allows the user to scroll through thebody sounds and voice tracks stored in the electronic storage medium forselection and playback. The microphone 48 may also be employed foractive ambient noise reduction to remove unwanted surroundingenvironmental noise from the recorded body and voice signal.

Referring back to FIG. 1, the electronic stethoscope 12 at the patientsite may be linked to or paired with the patient site computer 14 viathe secure wireless interface 26 to establish a secure networkconnection between the patient site electronic stethoscope 12 and thepatient site computer 14. Similarly, the electronic stethoscope 12 atthe specialist site may be linked to or paired with the specialist sitecomputer 22 via the secure wireless interface 28 to establish a securenetwork connection between the specialist site electronic stethoscope 12and the specialist site computer 22. While a single electronicstethoscope 12 is shown at each of the patient and specialist sites, itwill be appreciated that a plurality of electronic stethoscopes 12 maybe linked to the patient site computer 14 and/or the specialist sitecomputer 22. In some embodiments, the electronic stethoscopes 12 arepaired with their respective computers 14, 22 via a personal areanetwork (PAN). One example of a PAN is a Bluetooth network, in which apairing code is established on one of the electronic stethoscope 12 andcomputer 14 or 22, and entered on the other of the electronicstethoscope 12 and computer 14 or 22. In some embodiments, the optionalwireless headset 26 is also linked to or paired with the specialist sitecomputer 22 via the secure wireless interface 28.

A secure connection is also established between the network portinterfaces 27, 29 of computers 14, 22, respectively, over the Internet Isuch that the electronic stethoscopes 12 can communicate with each otherover a secure network connection. For example, the network portinterfaces 27, 29 may exchange certificates, require authentication, orestablish secure network keys to establish a secure connection. The datamay also be encrypted by the computers 14, 22 prior to sending the dataover the Internet I. The secure network key may then be employed todecrypt the data when received. In some embodiments, the network portinterfaces 27, 29 allow applications on the computers 14 and 22 tointerface with the wireless interfaces 26, 28 remotely across theInternet I.

In an alternative embodiment, the electronic stethoscopes 12 areconfigured to communicate with each other directly via a secureconnection (i.e., without interfacing with the computers 14 and 22). Forexample, each electronic stethoscope 12 may be configured with a uniqueInternet Protocol (IP) address, and the electronic stethoscopes 12 mayestablish a secure connection with each other directly using a wirelessfidelity (WiFi) connection or other wireless connection. As anotherexample, the patient site and/or specialist site may include a pluralityof electronic stethoscopes 12 that communicate with each other locally.

When the electronic stethoscopes 12 are linked over a secure networkconnection, signals may be sent between the electronic stethoscopes 12,or between the electronic stethoscopes 12 and the computers 14, 22, insubstantial real-time. For example, body sounds may be transmitted fromthe electronic stethoscope at the patient site to the ear tips 30 a, 30b at the specialist site in substantial real-time. The body sounds mayalso be reproduced in substantial real-time by speakers connected to thecomputers 14, 22. In some embodiments, the electronic stethoscopes 12 atthe patient and specialist sites are substantially identical such thatthe body and other sounds are reproduced substantially identically inthe ear tips 30 a, 30 b at the patient site and the specialist site. Inaddition, sounds may be recorded and stored by one of the electronicstethoscopes 12 and later played (either from the memory in theelectronic stethoscope 12 or from one of the computers 14, 22) atsubstantially the same time to all networked electronic stethoscopes 12.In some embodiments, the signals transmitted by the patient siteelectronic stethoscope 12 to the patient site computer 14 and over theInternet I are packetized and enumerated by the patient site electronicstethoscope 12, and undergo an error check at the specialist site toassure faithful sound quality and reliable reproduction at thespecialist site electronic stethoscope 12. The error check may beperformed by each element of the telemedicine system 10 (i.e., patientsite computer 14, specialist site computer 22, and specialist siteelectronic stethoscope 12) as a further assurance of accuratetransmission of data from the patient site electronic stethoscope 12.The error check may be any use suitable data transmission checktechniques, including, but not limited to, cyclic redundancy check(CRC), checksum, horizontal and vertical redundancy check, hashfunction, repetition code, and the like. The system may alsoincorporate, for example, sample throughput measurements, performed todetermine excess data or data starvation in the communication link. Inshort, the sound packets from the patient site electronic stethoscope 12are directly relayed (i.e., mirrored) over the Internet I to thespecialist site electronic stethoscope 12.

In preferred embodiments, the telemedicine system 10 includes an errorcheck and validation independent of the underlying communication systemor network (e.g., Bluetooth, TCP/IP) protocol. The independent errorcheck may be performed at any component of the telemedicine system 10 asa further assurance that the signal is a faithful reproduction of theauscultation sounds from the patient site electronic stethoscope 12. Incertain preferred embodiments, interruptions in service of theunderlying system are classified according to duration and severity,with all errors resulting in a communication to the user (via one ormore components of the telemedicine system) that the signal is not afaithful reproduction. For example, a patient site component may send apacketized or other signal to a specialist site system component everyother 500 milliseconds. An interruption in the underlying communicationsystem or network exceeding 500 milliseconds may result in a droppedpacket/signal and a resultant indication at the specialist site ofdegraded sound quality (e.g., via changing color of an indicator).

In addition, ambient sounds, such as voice signals, can be received bythe sensor 38 and transmitted between the electronic stethoscopes 12 insubstantial real-time, simultaneously or alternatingly with the bodysounds. In alternative embodiments, the electronic stethoscopes 12 canreceive voice communications and other ambient sounds through themicrophone 48 that are processed and communicated to the remote site.The body sound information is continuously streamed from the patientsite electronic stethoscope 12 to the specialist site electronicstethoscope 12, while the ambient sounds are streamed in both directionsbetween the patent and specialist site electronic stethoscopes 12. Thepatient site electronic stethoscope 12, specialist site electronicstethoscope 12, patient site computer 14, and specialist site computer22 may each include one or more ring buffers to assure a continuousstream of information between the electronic stethoscopes 12. In someembodiments, the ambient sounds are μ-law encoded and superimposed overthe body sounds generated by the electronic stethoscope 12 at thepatient site. Thus, the clinician at the patient site can hear the bodysounds from the patient while receiving voice instructions from thespecialist at the specialist site, for example. This allows thespecialist at the specialist site to have a substantially hands-onexperience with the patient. Because the clinician at the patient sitereceives the sound through the ear tips 30 a, 30 b, the clinician at thepatient site and the specialist at the specialist site can consultprivately, rather than having the specialist site communications outputthrough speakers attached to the patient site computer 14, for example.Signal processing may be employed to optimize the sound quality of thevoice signals provided through the ear tips 30 a, 30 b.

The voice and auscultations sounds reproduced through the ear tips 30 a,30 b of the electronic stethoscopes 12 at the patient and specialistsites may be controlled locally at each electronic stethoscope 12. Theauscultation and voice signals may be provided to the ear tips 30 a, 30b simultaneously, but on separate channels, allowing the clinician toseparately control the volume of the auscultation sounds and voicecommunications. This allows the clinician to optimize the relativevolumes of the auscultation and ambient sounds, providing the clinicianwith a balanced output to the ear tips 30 a, 30 b that is tailored tothe clinician's preferences. Each electronic stethoscope 12 may furtherinclude selectable voice enhancement filters that, for example, enhancecertain frequency bands of the voice signals to assist with ambientnoise reduction.

In some embodiments, the transmission of voice signals is selectablycontrolled while the stethoscopes are linked over the secure networkconnection. For example, when connected, the body sounds may beconstantly transmitted from the patient site to the specialist site,while the voice signals and other ambient sounds are transmitted betweenthe sites only when the clinician chooses to have the voice signalstransmitted. For example, in some embodiments the electronic stethoscope12 utilizes selective frequency filtering during auscultation tosuppress frequency bands characteristic of voice signals. In suchembodiments, the clinician may initiate the transmission of voicesignals by essentially deactivating the frequency filtering or modifyingthe filter settings (i.e., allowing reproduction and transmission ofonly certain frequency bands characteristic of voice signals). In someembodiments, transmission of the voice signals is initiated when theclinician presses a button on the user interface 40. The electronicstethoscope 12 may be configured such that the voice signals aretransmitted when the button on the user interface 40 is pressed and held(similar to a handheld transceiver or walkie-talkie). The electronicstethoscope 12 may alternatively be configured such that a voice signaltransmission mode is activated when the button is pressed and released,and the voice signal transmission mode is deactivated when the button issubsequently pressed and released again.

The electronic stethoscopes 12 may include an integrated software memorythat initially stores the software for the patient site softwareinterface 16 and/or the specialist site software interface 24. Forexample, the software may be included in each electronic stethoscope 12when the electronic stethoscope 12 is sold to a consumer. When theelectronic stethoscope 12 is paired with the computer 14 or 22, theelectronic stethoscope 12 may be configured to automatically loadsoftware stored in the software memory onto the computer 14 or 22. Whenthe software is installed on the computers 14, 22, the software allowsthe electronic stethoscopes 12 to interact with the computers 14, 22,such as by sending information and signals from the electronicstethoscopes 12 to the computers 14, 22 and providing control signalsfrom the computers 14, 22 to the electronic stethoscopes 12.

Also shown in FIG. 1 is a patient site televideo application 56 andserver site televideo application 58. In some embodiments, a videocamera is connected to the patient site computer 14 and/or thespecialist site computer 22 to allow video communications between thepatient site and the specialist site via the televideo applications 56and 58. This allows, for example, the specialist at the specialist siteto see the positioning of the sensor 38 relative to the patient at thepatient site and to provide feedback to the patient site about thepositioning of the sensor 38. As another example, the video cameras maybe used in conjunction with the microphones 48 on each of the electronicstethoscopes 12 to provide video conferencing between the patient siteand specialist site.

FIG. 3 is a front perspective view of an embodiment of a computer 60that is suitable for use as patient site computer 14 and/or specialistsite computer 22. The computer 60 includes a processor 62, a display 64,a camera 66, a keyboard 68, a mouse 70, and a communications adapter 72.The processor 62 is also configured for connection to the Internet tofacilitate communications between the patient site and the specialistsite. The processor 62 is shown as a laptop computer, but the processormay alternatively be a desktop computer or have any other form. Inaddition, while a separate display 64 is shown, the display of thelaptop computer may also be used. Furthermore, other input devices(e.g., trackball, joystick, etc.) may be integrated into the computer 60for use in the telemedicine system 10.

The processor 62 receives input control signals from the keyboard 68 andmouse 70, and provides video signals to the display 64. In addition, theprocessor 62 sends signals to and receives signals from the electronicstethoscope 12 via the communications adapter 72. In some embodiments,the communications adapter 72 is a Bluetooth dongle suitable forshort-range (e.g., up to 10 m) and medium-range (e.g., up to 100 m)secure communications. The keyboard 68 and the mouse 70 may be used toestablish a security code or the like to initiate a secure connectionwith the electronic stethoscope 12 as described above. Thecommunications adapter 72 may be positioned high on a wall as is shownto improve the line-of-sight and communications link between theelectronic stethoscope 12 and the communications adapter 72.

The camera 66 communicates with the processor 62 to capture video of thepatient or specialist site. The processor 62 then interfaces across theInternet I via the televideo application 56 or 58 to provide a livevideo feed to the patient or specialist site. The camera 66 may be amounted on the top of the display 64 as is shown to provide videocommunications between the patient and specialist sites as describedabove. The camera 66 may also be configured for wireless communicationwith the processor 62 to allow the camera 66 to be moved around thepatient or specialist site (e.g., to capture video of location of thesensor 38 on the patient). In some embodiments, the keyboard 68 and/ormouse 70 can be used at one site to control the operation of the camera66 (e.g., zoom, focus, position, etc) at the other site. This allows,for example, the specialist at the specialist site to control the videobeing captured at the patient site.

FIG. 4 is a screen shot of an embodiment of a user interface 80 that maybe displayed on the display 64 at the patient site during a telemedicinesession. The user interface 80 includes a data display module 82, avideo conference module 84, and a stethoscope control module 86. A userof the patient site computer 14 may use the keyboard 68, mouse 70,and/or other input devices to interact with the user interface on thedisplay 64. For example, the user may employ the mouse 70 to selectbuttons or pull-down menu elements on the user interface 80.

The data display module 82 is a graphical representation of a periodicbody sound generated by the patient and sensed by the sensor 38 at thepatient site. The signals generated by the sensor 38 are processed bythe electronic stethoscope processor and provided to the patient sitecomputer 14 via the integrated antenna. The processor 62 then processesthese signals and converts them into appropriate form for display on thedata display module 82. The graph can be updated periodically or insubstantial real-time while the clinician holds the electronicstethoscope 12 against the patient's body. The scale used or the axes inthe graph can be manipulated using the radio buttons 88 on the datadisplay module.

In some embodiments, the electronic stethoscope processor separates thesignals generated by the sensor 38 into a plurality of channels. Forexample, the electronic stethoscope processor may convert the sensedbody sounds to data signals representative of the sensed body sounds andsend the data signals to the patient site computer 14 on a firstchannel, and may convert the sensed body sounds to acoustic signals andsend the acoustic signals to the ear tips 30 a, 30 b on a secondchannel. Alternatively, the signals generated by the sensor 38 may besent directly to the patient site computer 14 for conversion to datasignals for display the processor 62.

The video conference module 84 displays the video being captured by thecamera 66 at the specialist site. This allows the clinician at thepatient site to see the specialist at the specialist site, and permitsthe specialist to demonstrate preferred positioning of the sensor 38relative to the patient at the patient site, for example. The videoconference module 84 also includes a toolbar 90 including a variety ofvideoconferencing controls. For example, the toolbar 90 may includebuttons to control the volume of sound received from the specialist siteand the positioning of the video conference on the user interface 80.The toolbar 90 may also include interfaces and tools to start and endthe video conference.

The stethoscope control module 86 may include a variety of selectablecontrols and settings for the electronic stethoscope 12 at the patientsite. These settings may be chosen to control the modes, volume, powerstate, recording settings, and the like of the patient site electronicstethoscope 12. In some embodiments, these settings are also selectablevia the user interface 40 on the electronic stethoscope 12. Thestethoscope control module 86 may also include options for controllingother modules on the user interface 80. The stethoscope control module86 may further include selectable options for the communication settingsbetween the electronic stethoscope 12 and the patient site computer 14.For example, the stethoscope control module 86 may allow for adjustmentof the packetization settings of the electronic stethoscope 12, or tocheck and repair the connection settings between the electronicstethoscope 12 and the patient site computer 14.

FIG. 5 is a screen shot of an embodiment of a user interface 100 thatmay be displayed on the display 64 at the specialist site during atelemedicine session. Similar to the user interface 80, the userinterface 100 includes a data display module 102, a video conferencemodule 104, and a stethoscope control module 106. A user of thespecialist site computer 22 may use the keyboard 68, mouse 70, and/orother input devices to interact with the user interface on the display64. For example, the user may employ the mouse 70 to select buttons orpull-down menu elements on the user interface 100.

The data display module 102 is a graphical representation of a periodicbody sound generated by the patient and sensed by the sensor 38 at thepatient site. The signals generated by the sensor 38 are processed bythe electronic stethoscope processor, provided to the patient sitecomputer 14, and sent to the specialist site computer 22. The specialistsite computer processor 62 then processes these signals and convertsthem into appropriate form for display on the data display module 102.The graph can be updated periodically or in substantial real-time whilethe clinician at the patient site holds the electronic stethoscope 12against the patient's body. The scale used or the axes in the graph canbe manipulated using the radio buttons 108 on the data display module.

The video conference module 104 displays the video being captured by thecamera 66 at the patient site. This allows the specialist at thespecialist site to see the positioning of the sensor 38 relative to thepatient at the patient site, for example. The video conference module104 also includes a toolbar 110 including a variety of videoconferencingcontrols. For example, the toolbar 110 may include buttons to controlthe volume of sound received from the patient site and the positioningof the video conference on the user interface 100. The toolbar 110 mayalso include interfaces and tools to start and end the video conference.The toolbar 110 may also include controls to adjust the camera positionat the patient site.

The stethoscope control module 106 may include a variety of selectablecontrols and settings for the electronic stethoscopes 12 at the patientsite and/or the specialist site. These settings may be chosen to controlthe modes, filtering, volume, power state, recording settings, and thelike of the patient and/or specialist site electronic stethoscopes 12.For example, the stethoscope control module 106 may include an interfaceto control the mode and filter settings on patient site electronicstethoscope 12. The stethoscope control module 106 may also beconfigured to allow control of some settings on the patient siteelectronic stethoscope 12, while leaving other settings for only localcontrol. For example, the stethoscope control module 106 may providevolume control for only the specialist site electronic stethoscope 12,while the volume for the patient site electronic stethoscope 12 is onlycontrollable at the patient site (e.g., via the stethoscope controlmodule 86 or the user interface 40 on the patient site electronicstethoscope 12). In some embodiments, the specialist site electronicstethoscope 12 may also be configured such that the user interface 40 onthe specialist site electronic stethoscope 12 controls settings of thepatient site electronic stethoscope 12 when connected over a securenetwork. The specialist site electronic stethoscope 12 may also beconfigured to control substantially all of the settings on the patientsite electronic stethoscope 12 (i.e., local control at the patient siteis essentially disabled), while still allowing the patient site tocontrol of volume. Such local control ensures that volume may beadjusted according to user preference at each location.

In an alternative embodiment, the clinician at the specialist site mayset the specialist site electronic stethoscope 12 to the desiredsettings and subsequently send the settings of the specialist siteelectronic stethoscope 12 to the patient site electronic stethoscope 12(e.g., via the specialist site computer 22 and the patient site computer14) in one transmission to update the settings on the patient siteelectronic stethoscope 12.

The stethoscope control module 106 may further include selectableoptions for the communication settings between the patient siteelectronic stethoscope 12 and the patient site computer 14 and/or thespecialist site electronic stethoscope 12 and the specialist sitecomputer 22. For example, the stethoscope control module 106 may allowfor adjustment of the packetization settings of the electronicstethoscope 12, or to check and repair the connection settings betweenthe electronic stethoscope 12 and the specialist site computer 22.

The user interface 100 shown and described is merely exemplary and otherconfigurations for the user interface are possible. In one exemplaryalternative configuration, shown in FIG. 6, the user interface 100 mayinclude a first graphical user interface 112 that is a feature enhancedimage of the housing 36 on the specialist site electronic stethoscope12, having a control section 114 including each of the buttons and otherinterfaces on the user interface 40 on the specialist site electronicstethoscope 12. Each button on the control section 114 may be selectableto produce the same function on the specialist site electronicstethoscope 12 as if the corresponding button on the user interface 40were pressed. A user interface similar to user interface 112 may also bedisplayed on the user interface 80 to provide on-screen function controlfor the patient site electronic stethoscope 12.

When the specialist site electronic stethoscope 12 is connected to andsynchronized with the patient site electronic stethoscope 12, the userinterface 100 may display a single graphical user interface that is afeature enhanced image of the housing 36 on the patient site electronicstethoscope 12, including each the buttons and other interfaces on theuser interface 40 on the patient site electronic stethoscope 12. Thissame graphical user interface 112 may also be displayed on the userinterface 80. When the patient and specialist site electronicstethoscopes 12 are connected, each button on the graphical userinterface 112 may be selectable at either the patient or specialist siteto produce the same function on the patient site electronic stethoscope12 as if the corresponding button on the user interface 40 of thepatient site stethoscope were pressed. The graphical user interface 112provides the clinician at the specialist site with an interface throughwhich certain settings (e.g., mode, filters, etc.) of the patient siteelectronic stethoscope 12 are controllable.

The graphical user interface 112 may also include a plurality ofconnectivity buttons 116 that may be used to control the connectionbetween the specialist site computer and the connected electronicstethoscopes 12. For example, in the embodiment shown in FIG. 6, theconnectivity buttons 116 include a “Disconnect Scope” button that allowsfor disconnection of the local specialist site electronic stethoscope 12from the specialist site computer 22, a “Disconnect Remote” button thatallows for disconnection of the specialist site computer 22 (anddesynchronization of the specialist site electronic stethoscope 12) fromthe patient site electronic stethoscope 12, and a “Talk to Remote”button that activates voice communications between the specialist andpatient site electronic stethoscopes 12. When the specialist siteelectronic stethoscope 12 is not connected to the patient siteelectronic stethoscope 12, the “Disconnect Remote” and “Talk to Remote”buttons may be inactivated or may not appear on the graphical userinterface 112.

Additionally, the graphical user interface 112 may include an optionsmenu 117 that allows the user to control various options associated withthe connected electronic stethoscope 12. For example, in the embodimentshown in FIG. 6, the options menu 117 includes a pull-down menu thatallows the clinician to scroll between the stethoscopes connected to thespecialist site computer 22. This toggles the active electronicstethoscope 12 active on the graphical user interface 112, allowing theclinician to modify the settings for each of the connected stethoscopes.

The graphical user interface 112 may further include a visual and/oraudio indication that indicates that the sound heard by the clinician atthe specialist site electronic stethoscope 12 is a faithful reproductionof the sound from the patient site electronic stethoscope 12. In theembodiment shown in FIG. 6, the graphical user interface 112 includes afidelity gauge 118 labeled “Stream Integrity” that includes a fidelityindicator 119. The fidelity indicator 119 changes color to indicatewhether faithful sound reproduction is occurring at the specialist siteelectronic stethoscope 12. For example, the fidelity indicator 119 maybe displayed in green when the sound is a faithful reproduction and inred when the sound is not a faithful reproduction. This indication maybe based on the error detection (e.g., CRC) performed by the specialistsite computer 22 and/or the specialist site electronic stethoscope 12.The error detection may also be performed by the patient site computer14 and/or patient site electronic stethoscope 12. For example, if errorsare identified by either the specialist site computer 22 and/or thespecialist site electronic stethoscope 12, the specialist siteelectronic stethoscope 12 may send a signal to the specialist sitecomputer 22 that the data received by the specialist site electronicstethoscope 12 is not the same as the data sent by the patient siteelectronic stethoscope 12. The indication may then be provided by theuser interface 100, which shows the clinician at the specialist sitethat the sound being heard through the specialist site electronicstethoscope 12 is not a faithful reproduction of the body sound signalssensed by the patient site electronic stethoscope 12. The specialistsite electronic stethoscope 12, the patient site electronic stethoscope12, and/or the user interface 80 may also provide an indication offaithful sound reproduction. In alternative embodiments, the lack oferror is reported to system components.

While the electronic stethoscope 12 has been described with regard to astethoscope having a chestpiece, main tube, and binaurals connected toear tips, the electronic stethoscope used in the telemedicine system 10may have other configurations. For example, FIG. 7 illustrates awireless chestpiece 120 and FIG. 8 illustrates a wireless headset 122usable in association with the telemedicine system 10.

The wireless chestpiece 120 is configured substantially similarly to thechestpiece 36 described above with regard to FIG. 2, and interacts withelements of the telemedicine system 10 in substantially the same way asthe electronic stethoscope 12. In particular, the wireless chestpiece120 is configured to connect with the computers 14, 22 via a securenetwork connection. Components that may be disposed in the chestpiece120 include a power source, signal processing circuitry, and acommunications interface. A sensor 124 (not shown) is supported at oneend of the wireless chestpiece 120, and an antenna 126 is mounted at anend of the wireless chestpiece 120 opposite the sensor 124. In someembodiments (not shown), an antenna is integrated into the housing asdescribed above. The sensor 124 may have properties and configurationssimilar to those described above with regard to sensor 38. In theembodiment shown, the antenna 126 is configured to swivel or rotateabout pivot 128 to allow the antenna 126 to be positioned for maximumsignal coupling during use. The antenna 126 can also be positioned tominimize clearance during storage. In some embodiments, the antenna 126is a high performance antenna for large signal range (e.g., greater than100 m), thereby maximizing the mobility of the wireless chestpiece 120.

The wireless headset 122 is configured to receive signals from thewireless chestpiece 120 via a secure connection. In some embodiments,the chestpiece 120 and headset 122 are paired with each other via aBluetooth connection. The wireless headset 122 may also be configured tocommunicate with the computer 14 or 22, similar to the headset 26 shownin FIG. 1. The wireless headset 122 may have various configurations,including over-the-ear and in-ear designs. In the embodiment shown, thewireless headset 122 includes ear tips 130 a, 130 b for in-ear use. Insome embodiments, the ear tips 130 a, 130 b are substantially the sameas ear tips 30 a, 30 b in FIG. 2 to provide consistent sound quality tothe user between the electronic stethoscope 12 and the wireless headset122.

The wireless headset 122 may also include a microphone 132 for receivingvoice sounds from the user. The microphone 132 is coupled to anadjustable support 134 that allows the microphone 132 to be repositionedrelative the user. The signals received by the microphone 132 may besuperimposed over the body sounds sensed by the wireless headset 120 andsent over the Internet I, as described above.

In addition to the electronic stethoscope used in the telemedicinesystem 10 having alternative configurations, the connection between theelectronic stethoscopes may also have alternative configurations. Forexample, FIG. 9 is a diagrammatic view of a telemedicine system 150according to an alternative embodiment. The telemedicine system 150include a sensing electronic stethoscope 12 a, a plurality of networkedelectronic stethoscopes 12 b, 12 c, . . . , 12 n, and a networkinterface or hub 152. The electronic stethoscopes 12 a-12 n communicatedwirelessly with the network interface 152. The electronic stethoscopes12 a-12 n may be configured substantially similarly and havesubstantially similar properties as electronic stethoscope 12 describedabove in FIG. 2. It will be appreciated that electronic stethoscope 12 nis representative of the nth networked electronic stethoscope 12, andshould not be construed as limiting or defining the number of networkedelectronic stethoscopes 12 connected to the network interface 152. Insome embodiments, the network interface 152 is configured as a wearable,handheld, or portable device.

The network interface 152 is configured to establish a secure connectionwith the electronic stethoscopes 12 a-12 n. In some embodiments, theelectronic stethoscopes 12 a-12 n are paired with the network interface152 via a personal area network (PAN). One example of a PAN is aBluetooth network, in which a pairing code is established on the networkinterface 152 and entered on each electronic stethoscope 12 a-12 n tosecurely connect to the network interface 152. When connected, thesensing electronic stethoscope 12 a may be used to sense a patient'sbody sounds, while the networked electronic stethoscopes 12 b-12 n maybe used to listen to the patient body sounds sensed by the sensingelectronic stethoscope 12 a in substantial real-time. In addition, othersounds, such as voice prompts, may be received on a sensor 38 ormicrophone 48 of one of the electronic stethoscopes 12 a-12 n anddelivered to each of the networked electronic stethoscopes 12 a-12 n. Inalternative embodiments, the electronic stethoscopes 12 a-12 n arenetworked directly to each other (i.e., without interfacing with theintermediate network interface 152).

In one example implementation, a teacher's electronic stethoscope 12 andthe electronic stethoscopes 12 of one or more students may be networkedvia the network interface 152. The physician or a student may beselected to sense the patient's body sounds, while the other networkedusers listen to the patient's body sounds via their respectiveelectronic stethoscopes 12. In addition, sounds stored in the teacher'selectronic stethoscope 12 (or in another networked storage device) maybe played back at substantially the same time to all networkedelectronic stethoscopes 12. The physician may also provide voiceinstructions or prompts via the sensor 38 or microphone 48 on the mainhousing 36 that are provided through the ear pieces of the students'electronic stethoscopes 12 at the same time as the sensed body sounds.Thus, if the physician's electronic stethoscope is being used to sensebody sounds, the physician can demonstrate positioning and use of theelectronic stethoscope 12 a while the students listen on networkedelectronic stethoscopes 12 b-12 n. If a student's electronic stethoscopeis being used to sense body sounds, the physician can provideinstruction and guidance to the each of the students via the sensor 38or microphone 48. In addition, each of the students with an electronicstethoscope 12 networked to the network interface 152 can take a turnsensing the body sounds while the physician provides individual guidanceto them.

In other embodiments, networked scopes are connected to a computer orother external device (e.g., cell phone, PDA) as described above. Theauscultation sounds and voice signals of a networked scope may bereproduced in substantial real-time by speakers connected to thecomputer or other external device. In some embodiments, body sounds maybe downloaded from an electronic storage medium or other online database(e.g., website) to the computer or external device via a networkconnection and streamed to the networked stethoscopes and/or reproducedin substantial real time by speakers.

In summary, certain embodiments disclosed herein relate to atelemedicine system including a first electronic stethoscope including ahousing configured for hand-held manipulation by a clinician relative toa patient, a transducer supported by the housing and configured to senseauscultation signals from the patient at a first location, and a headsetcoupled to the housing and configured to deliver audio corresponding tothe auscultation signals through earpieces on the headset. Thetelemedicine system further includes a second electronic stethoscopeincluding a housing, transducer, and headset substantially similar tothe housing, transducer, and headset of the first electronicstethoscope. The first electronic stethoscope is configured to convertthe auscultation signals to digital signals representative of theauscultation signals and to wirelessly transmit the digital signals to asecond location via a secure digital network. The second electronicstethoscope is configured to receive the digital signals representativeof the auscultation signals at the second location via the securedigital network, to convert the digital signals to audio correspondingto the auscultation signals, and to deliver the audio through earpieceson the headset of the second electronic stethoscope in substantial realtime with the sensing of the auscultation sounds at the first location.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. For example, while the embodiments described above refer toparticular features, the scope of this invention also includesembodiments having different combinations of features and embodimentsthat do not include all of the described features. Accordingly, thescope of the present invention is intended to embrace all suchalternatives, modifications, and variations as fall within the scope ofthe claims, together with all equivalents thereof.

The invention claimed is:
 1. A telemedicine system comprising: a firstelectronic stethoscope comprising a housing configured for hand-heldmanipulation, a transducer that senses auscultation signals at a firstlocation, and a headset that delivers audio corresponding to theauscultation signals through earpieces on the headset, the firstelectronic stethoscope further comprising a processor that converts theauscultation signals to digital signals representative of theauscultation signals and an antenna to wirelessly transmit the digitalsignals to a second location via a secure digital network; and a secondelectronic stethoscope comprising a housing configured for hand-heldmanipulation, a transducer, and a headset that delivers audio throughearpieces on the headset, the second electronic stethoscope furthercomprising an antenna to receive the digital signals representative ofthe auscultation signals at the second location via the secure digitalnetwork, and a processor to convert the digital signals to audiocorresponding to the auscultation signals and deliver the audio throughearpieces on the headset of the second electronic stethoscope insubstantial real time with the sensing of the auscultation sounds at thefirst location, wherein the transducer on the first electronicstethoscope further receives ambient audio at the first location and thetransducer on the second electronic stethoscope further receives ambientaudio at the second location, and wherein the ambient audio istransmitted wirelessly between the first and second locations via thesecure digital network.
 2. A telemedicine system comprising: a firstelectronic stethoscope comprising a housing configured for hand-heldmanipulation, a transducer that senses auscultation signals at a firstlocation, and a headset that delivers audio corresponding to theauscultation signals through earpieces on the headset, the firstelectronic stethoscope further comprising a processor that converts theauscultation signals to digital signals representative of theauscultation signals and an antenna to wirelessly transmit the digitalsignals to a second location via a secure digital network; and a secondelectronic stethoscope comprising a housing configured for hand-heldmanipulation, a transducer, and a headset that delivers audio throughearpieces on the headset, the second electronic stethoscope furthercomprising an antenna to receive the digital signals representative ofthe auscultation signals at the second location via the secure digitalnetwork, and a processor to convert the digital signals to audiocorresponding to the auscultation signals and deliver the audio throughearpieces on the headset of the second electronic stethoscope insubstantial real time with the sensing of the auscultation sounds at thefirst location, wherein the first electronic stethoscope is configuredto receive control signals via the secure digital network to allowmodification of settings of the first electronic stethoscope from thesecond location.
 3. The telemedicine system of claim 1 or 2, wherein theaudio delivered to the headset of the second electronic stethoscope is afaithful reproduction of the auscultation sounds at the first location.4. The telemedicine system of claim 1, wherein the transducer isactivated to receive ambient audio at the first location upon actuationof a user interface element on the first electronic stethoscope, andwherein the second transducer is activated to receive ambient audio atthe second location upon actuation of a user interface element on thesecond electronic stethoscope.
 5. The telemedicine system of claim 4,wherein the processor of the first electronic stethoscope comprises afrequency filter, and wherein actuation of the user interface element ofthe first electronic stethoscope modifies a setting of the frequencyfilter.
 6. The telemedicine system of claim 1 or 2, wherein the firstelectronic stethoscope communicates with a first computer at the firstlocation via a first secure personal area network and the secondelectronic stethoscope communicates with a second computer at the secondlocation via a second secure personal area network, and wherein thefirst computer transmits the digital signals representative of theauscultation signals to the second computer via a secure digitalconnection.
 7. The telemedicine system of claim 6, wherein at least oneof the first stethoscope, second stethoscope, first computer, and thesecond computer provides an audio and/or visual indication when theaudio delivered through the earpieces on the headset of the secondelectronic stethoscope is a faithful reproduction of the auscultationsignals sensed by the first electronic stethoscope.
 8. The telemedicinesystem of claim 1 or 2, wherein the antenna of each of the first andsecond electronic stethoscopes is disposed at least partially in theheadset.
 9. The telemedicine system of claim 1 or 2, wherein the firstelectronic stethoscope is further configured to wirelessly receivesignals from the second electronic stethoscope via the secure digitalnetwork.
 10. The telemedicine system of claim 1 or 2, wherein the secondlocation is remote from the first location.
 11. The telemedicine systemof claim 2, wherein the control signals prevent modification of certainsettings of the first electronic stethoscope at the first location. 12.The telemedicine system of claim 11, wherein the control signals do notprevent modification of volume settings of the first electronicstethoscope at the first location.
 13. The telemedicine system of claim1 or 2, wherein at least one of the first and second electronicstethoscopes comprises a wireless chestpiece and a wireless headset.